Permanent redirection with regex after moving blog

[Igor Sysoev]

On Thu, Aug 13, 2009 at 04:05:46PM +0300, Marcus Clyne wrote:

> Igor Sysoev wrote:
> >On Thu, Aug 13, 2009 at 12:43:14PM +0300, Marcus Clyne wrote:
> >
> >  
> >>miles wrote:
> >>    
> >>>location ^~ /weblog/ {
> >>>rewrite ^/weblog/(.*) /blog/$1 permanent;
> >>>}
> >>>
> >>>location ~ ^/weblog/(.*) {
> >>>rewrite ^ /blog/$1 permanent;
> >>>}
> >>>
> >>>You should use the first method.
> >>>
> >>>Thanks so much, Igor - will do!
> >>>
> >>>Posted at Nginx Forum: 
> >>>http://forum.nginx.org/read.php?2,4895,4912#msg-4912
> >>>
> >>> 
> >>>      
> >>Would
> >>
> >>location /weblog/ {
> >>rewrite ^/weblog/(.*) /blog/$1 permanent;
> >>}
> >>
> >>not be a little more efficient?
> >>    
> >
> >"location ^~ /weblog/" is more efficient than "location /weblog/" because
> >"^~" disables testing any regex locations. If server has no regex 
> >locations,
> >then these two locations are equal.
> >
> >  
> What about when you have no regexes - will the non-regex location be 
> marginally faster because it doesn't involve the pcre library (i.e. just 
> strncmp) (I've not looked at that bit of source code, but I'm assuming 
> you don't use the overhead of initing a pcre struct for just checking 
> the first characters of the uri)?

Static locations are better because:

1) they are slightly faster, nginx looks them in some kind of binary tree
   with addition of inclusive nodes, while regex location are run until
   one will match.

2) static locations allow to write scalable configurations: you just
   need to add yet another location and you do not worry about some
   conflicts with other locations: for example, at the moment I have
   158 static (and only static!) locations at www.rambler.ru.

As to regexes, if you write "~/~*" then nginx calls PCRE without
any checking and optimizations. BTW, PCRE does not test "\.(gif|jpg|...)$"
or even "\.php$" from the end as perl does. Probably, it should be
optimized, at least the later case.


-- 
Igor Sysoev
http://sysoev.ru/en/